Launched air vehicle system

ABSTRACT

A launch canister for ejection from a submerged launch platform, the launch canister being adapted for ejection in a direction substantially along a first axis of the launch canister and comprising: an enclosure for carrying a UAV; a nose cap releasably located in a launch opening at a forward end of the launch canister; a launch mechanism for driving a UAV carried in the enclosure out of the launch canister through the launch opening in a direction substantially along said first axis; and a water surface sensor for detecting when the nose cap of the canister broaches the surface of the water; wherein the launch canister is configured to, on the water surface sensor detecting that the nose cap of the canister has broached the surface of the water, immediately release the nose cap and initiate the launch mechanism to drive a UAV carried in the enclosure out of the launch canister through the launch opening.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/294,073, filed Jun. 2, 2014, entitled “LAUNCHED AIR VEHICLE SYSTEM”,which claims foreign priority benefits under 35 U.S.C. § 119(a)-(d) or35 U.S.C. § 365(b) of British application number 1309841.3, filed Jun.3, 2013, the entire contents of all of which are incorporated herein byreference in their entireties.

FIELD

This invention relates to a launch canister for providing a UAV intoairspace above a submerged launch platform.

BACKGROUND

Launching unmanned aerial vehicles (UAVs) from a submarine whilst thesubmarine is submerged poses a difficult problem. Conventional launchsolutions that might be used on land or on ships are not suitable foruse on submarines because they are designed to launch UAVs into clearair, not through a layer of water. Furthermore, UAVs are not typicallydesigned for travel through water and could be damaged if launched intowater.

Systems for launching UAVs from a submarine are currently indevelopment. The first of these, Gabler's VOLANS system avoids theproblem of launching through water by providing a dedicated submarinemast from which a UAV can be unfolded and launched using a catapult (theUAV hence being above the surface of the water on launch). However, thissystem requires a submarine to be heavily modified so as to carry theadditional launch mast. It is also limited in that the submarine can beno deeper than periscope depth with the launch mast being required tobreak through the surface of the water in order to launch its UAV.

Raytheon Company of Waltham (Mass.), US, is also developing a UAV launchsystem for submarines, SOTHOC, which makes use of a submarine launchvehicle adapted for ejection from the garbage ejector of a submarine.The submarine launch vehicle carries the UAV to the surface by inflatinga float collar and then makes use of a water drogue and vane tostabilise and align a launch tube at a 35 degree angle into the wind.The UAV is launched from the launch tube of the submarine launch vehicleby means of a conventional launch mechanism. Whilst the SOTHOC systemallows a UAV to be launched while the submarine is submerged, the systemsuffers from the problems that many modern submarines do not havegarbage ejector systems and the system is unreliable in rough seas.Furthermore, garbage ejector guns are reliant on the ability to draindown the water from inside the ejector to an internal waste water tank.If the tank is full or near to full then the internal waste water tankwill have to be pumped overboard, which is a noisy procedure and mightnot therefore be possible if the submarine is to maintain a low acousticsignature. U.S. Pat. No. 7,946,241 discloses more detail of thefloatable housing for deployment of an unmanned aerial vehicle adaptedto be launched from a marine vessel.

A third system, the Lockheed Martin Cormorant, has previously beenproposed at a conceptual level. The Cormorant was a 4-ton UAV havingfolding wings so as to allow it to fit into a Trident missile tube. Inorder to launch the Cormorant UAV, it was not fired from the tube butguided out on a “saddle” at a depth of 150 feet and left to float to thesurface, during which time it unfolded its wings. The UAV's rockets werethen used to lift the UAV away from the water surface and into flight.Due to its cost this project was not pursued.

There is therefore a need for improved apparatus for launching UAVs froma submarine.

SUMMARY

According to an aspect, there is provided a launch canister for ejectionfrom a submerged launch platform, the launch canister being adapted forejection in a direction substantially along a first axis of the launchcanister and comprising: an enclosure for carrying a UAV; a nose capreleaseably located in a launch opening at a forward end of the launchcanister; a launch mechanism for driving a UAV carried in the enclosureout of the launch canister through the launch opening in a directionsubstantially along said first axis; and a water surface sensor fordetecting when the nose cap of the canister broaches the surface of thewater; wherein the launch canister is configured to, on the watersurface sensor detecting that the nose cap of the canister has broachedthe surface of the water, immediately release the nose cap and initiatethe launch mechanism to drive a UAV carried in the enclosure out of thelaunch canister through the launch opening.

According to another aspect, there is provided a method for launching anunmanned aerial device from a submerged launch platform, the methodcomprising: ejecting a launch canister carrying an unmanned aerialvehicle in an enclosure thereof in a direction substantially along afirst axis of the launch canister, detecting a nose cap located in alaunch opening of the launch canister broaching the surface of thewater, in response to detecting the nose cap broaching the surface ofthe water, immediately releasing the nose cap and initiating a launchmechanism to drive the unmanned aerial vehicle out of the launchcanister through the launch opening, and driving the unmanned aerialvehicle out of the launch canister by the launch mechanism through thelaunch opening in a direction substantially along said first axis.

According to a yet further aspect, there is provided a computer programcomprising code means adapted to control, when run on processorapparatus, operations in association with launch of an unmanned aerialdevice from a submerged launch platform, the operations comprising:receiving a signal indicating that a nose cap located in a launchopening of a launch canister carrying the unmanned aerial vehicle andejected in a direction substantially along a first axis of the launchcanister has broached the surface of the water; in response to thesignal, immediately causing release of the nose cap and initiation of alaunch mechanism to drive the unmanned aerial vehicle out of the launchcanister through the launch opening; and causing driving of the unmannedaerial vehicle out of the launch canister by the launch mechanismthrough the launch opening in a direction substantially along said firstaxis.

Preferably the launch mechanism is a high pressure gas charge.

Suitably the launch mechanism is initiated in response to the nose capbeing released.

Suitably the nose cap is connected to the launch canister by means of asprung hinge, said hinge being biased so as to rotate the nose cap awayfrom the launch opening when the nose cap is released. Alternatively,the nose cap is connected to the launch canister by means of one or moreexplosive pins, the nose cap being released from the launch opening byfiring the explosive pins so as to drive the nose cap away from thelaunch opening.

Suitably the launch mechanism is an explosive or high pressure gascharge and the nose cap is connected to the launch canister by one ormore mechanical locks, the nose cap being released from the launchopening by releasing the locks and allowing the gas developed by theexplosive or high pressure gas charge to drive the nose cap from thelaunch canister.

Preferably the nose cap is configured to make a watertight fit with thelaunch opening so as to prevent the ingress of water into the enclosureduring the passage of the launch canister through water.

Preferably the water surface sensor comprises at least one of ahydrostatic switch, a pressure switch, electronic switch, and an electrooptical switch.

The launch canister suitably further comprises one or more guideelements adapted to direct the motion of the launch canister towards thewater surface at a preferred launch angle.

Suitably the one or more guide elements include steer-away fins or aflotation device.

The launch canister preferably further comprises a first lanyard fixedlyattached at one end to an external part of the launch canister andhaving its other end adapted for detachable connection to a submergedlaunch platform, the launch canister being configured such that, whenthe launch canister is ejected from a submerged launch platform, the oneor more guide elements move from a stowed to a deployed position on thefirst lanyard pulling taut at a first extension of the first lanyard,the first extension of the first lanyard being such that the one or moreguide elements are deployed on the launch canister fully exiting thesubmerged launch platform. Preferably the first lanyard is configured todetach from the submerged launch platform on the first lanyard pullingtaut at a second extension of the first lanyard.

Suitably the one or more guide elements are configured to automaticallydeploy on exit from the launch mechanism.

Suitably the launch mechanism comprises a launch tube from which thelaunch canister is ejected, the one or more guide elements includingspring-loaded steer-away fins arranged to spring into a deployedposition on exiting the confined space of the launch tube.

Suitably the launch mechanism comprises a launch tube from which thelaunch canister is ejected, the one or more guide elements including aflotation collar and the launch canister comprising a switch mechanismarranged to cause the flotation collar to inflate on the launch canisterexiting the confined space of the launch tube.

The launch canister preferably further comprises a second lanyardattached at one end in the enclosure and having its other end adaptedfor detachable connection to a UAV, wherein the length of the secondlanyard is selected such that, when a UAV connected to the secondlanyard is driven from the launch canister, the second lanyard pullstaut and detaches from the UAV as the engine of the UAV passes throughthe launch opening. Preferably said other end of the second lanyard isadapted to cause an engine of the UAV to power up on pulling taut anddetaching from the UAV.

Suitably the enclosure is adapted for carrying a UAV having stowedwings, the enclosure including one or more guide pieces for guiding thepassage of stowed wings of a UAV on such UAV being driven from thelaunch canister.

Suitably the submerged launch platform is a submarine. Suitably thelaunch canister is adapted for launch from a Submerged Signal Ejectortube or an Under Casing Launcher.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described by way of example withreference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a launch canister configured inaccordance with the present invention.

FIGS. 2A-E is an illustration of a UAV launch by means of a launchcanister configured in accordance with the present invention.

FIG. 3 is a schematic diagram of a launch canister configured inaccordance with the present invention and located in an Under CasingLauncher.

FIG. 4 is an illustration of a UAV launch by means of a launch canisterconfigured in accordance with the present invention and ejected from anUnder Casing Launcher.

FIG. 5 is a flowchart according to one embodiment.

FIG. 6 shows a control apparatus.

DETAILED DESCRIPTION

The following description is presented to enable any person skilled inthe art to make and use the invention, and is provided in the context ofa particular application. Various modifications to the disclosedembodiments will be readily apparent to those skilled in the art.

The general principles defined herein may be applied to otherembodiments and applications without departing from the spirit and scopeof the present invention. Thus, the present invention is not intended tobe limited to the embodiments shown, but is to be accorded the widestscope consistent with the principles and features disclosed herein.

The present invention relates to a canister adapted for ejection throughwater and carrying a UAV for delivery into the airspace above thesubmerged launch platform, which could be a boat, submarine, SwimmerDelivery Vehicle (SDV) or other submerged structure. A launch canisteras described herein could be adapted for ejection from any kind ofunderwater launch apparatus, but it is particularly advantageous if alaunch canister configured in accordance with the present invention isadapted for ejection from a Submerged Signal Ejector (SSE) or UnderCasing Launcher (UCL) present in modern submarines. Such launchmechanisms allow rapid deployment of equipment whilst submerged withouttying up missile or torpedo launch tubes. In the examples given hereinit will be assumed that the launch platform is a submarine.

It is envisaged that a launch canister of the present invention would belaunched from a submarine at approximately periscope depth. However,since the launch mast does not need to be raised the submarine canremain entirely submerged.

A launch canister for a UAV configured in accordance with the presentinvention is shown in FIG. 1. The launch canister 100 comprises awatertight enclosure 101 adapted to carry an Unmanned Aerial Vehicle(UAV) 102. UAV 102 would preferably have stowable wings 110 and tailplanes 111 so as to allow the UAV to adopt a compact configuration thatmakes efficient use of space in enclosure 101. The wings could, forexample, be of a switchblade or wrap-around design. The UAV propellercould also be foldable. Since the external diameter of the launchcanister is constrained by the particular requirements of the mechanismby which it is launched, such spacing-saving features permit a UAV to becarried in launch canisters smaller than the size of the UAV with allits flight surfaces deployed.

Enclosure 101 is closed off by a nose cap 103 which makes a watertightseal in launch opening 108. Nose cap 103 is configured to uncover launchopening 108 in order to allow UAV 102 to be launched out of itsenclosure. This could be achieved in any number of ways, for example:

-   -   i. the nose cap could be mounted to the launch canister by a        sprung hinge that is biased such that when the nose cap is        released the nose cap flips away from the launch opening by        rotating about the hinge;    -   ii. the nose cap could be connected to the launch canister by        means of one or more explosive pins arranged to, on their        activation, jettison the nose cap;    -   iii. the nose cap could be held in place by means of one or more        locks, those locks being released immediately prior to launch of        the UAV so as to allow the UAV to push the nose cap out of the        way as it exits the canister (in the case that the UAV is driven        out of the canister by an explosive or compressed gas charge it        could be the rapidly expanding gas itself that pops of the nose        cap);    -   iv. the nose cap could comprise a waterproof diaphragm through        which the UAV is forced on being driven from the launch        canister—in this case there need not be any explicit release of        the nose cap since it stays in place during launch, but the        canister could additionally include a further protective nose        cap over the diaphragm that is released on the canister        broaching the water surface.

Launch canister 100 includes a launch mechanism 104 arranged to drivethe UAV out of the canister through launch opening 108. Launch mechanism104 could be any suitable kind of mechanism for launching the UAV,including a mechanical device (e.g. a catapult or other sprungmechanism), an explosive charge, or a compressed gas charge. Preferablythe launch mechanism is a compressed gas charge since this can be storedin a quiescent state for long periods of time, has a lower acousticsignature than an explosive charge, and means that the canister need notbe handled as an explosive, which improves platform safety.

The launch canister itself is designed to be ejected from a submarine,typically from a launch tube using a compressed gas charge or anair/water ram discharge mechanism. Irrespective of the particular meansby which the canister is launched, the launch canister is adapted to belaunched nose cap first in a direction substantially commensurate withthe direction in which the UAV is to be launched out of the canister.This direction is indicated by arrow 106 in FIG. 1 and is definedrelative to the canister, not its launch platform.

Launch canister 100 further comprises a surface sensor 107 for detectingwhen the nose cap reaches the surface of the water. The surface sensorcould be any kind of suitable sensor, such as a hydrostatic switch, oran electronic sensor for detecting the transition from water to air.Other examples include a pressure switch or an electro-optical sensorfor detecting the transition from water to air can be provided. On thesurface sensor detecting the water surface, the nose cap of the launchcanister is released in accordance with whichever mechanism the nose capis attached to the canister (e.g. by releasing one or more electroniclocks, activating one or more explosive pins etc.).

In accordance with a possibility, a launch canister may have an on-boardfitted Inertial Measurement Unit (IMU) to detect the motion of thelaunch canister. The IMU can signal canister motion data to controlelectronics of the UAV to assist in the discharge initiation sequenceand subsequent ejection of the UAV from the canister. Furthermore, apositioning system unit may also be provided in the UAV and/or in thecanister. For example, the UAV may comprise a Global Positioning System(GPS) receiver. The canister motion data along with the GPS receiveracquiring a GPS satellite lock can be used to determine when thecanister has surfaced and the UAV is ready for the on-board controlsystem electronics to initiate a discharge sequence from the enclosure.

The launch canister may optionally further comprise a UAV lanyard 109connected between the UAV and the launch canister. This provides a meansfor causing the engine of the UAV to initiate at the correct moment.Lanyard 109 is detachable from the UAV at switch 112 on the lanyardpulling taut at its maximum extension. Switch 112 is preferably used toactivate the UAV engine so as to cause the UAV to enter powered flight.Thus, on the lanyard pulling taut at its maximum extension, switch 112activates the UAV engine and the lanyard detaches from the switchmechanism. Switch 112 could be any type of mechanical or electricalswitch. Most preferably, the length of the lanyard is selected such thatit pulls taut and activates the UAV engine as the engine of the UAVemerges through the launch opening. This allows the UAV to achievecruise speed (typically 25-30 knots) by the time the wings are fullydeployed. For example, if the UAV has a nose-mounted propeller engine,the lanyard length is selected so as to cause the engine to activate asthe nose of the UAV exits through the launch opening of the canister.

Alternatively, the UAV includes a switch that is engaged by the actionof the UAV wings being deployed as the UAV exits the canister,engagement of the switch causing the UAV engine to power up. Preferablythe switch would be engaged on the UAV wings locking into position atfull deployment.

It is advantageous if lanyard 109 is further configured to provide powerand/or data to the UAV. This allows initialisation and navigation datato be uploaded to the UAV prior to its launch.

On the UAV being ejected from the launch canister, the wings and/or tailplanes of the UAV are deployed. This is preferably achieved by havingthe wings and/or tail planes sprung such that they extend into theirflight configuration on exiting the confines of the enclosure. The wingsand/or tail would preferably then lock into their flight position, forexample through the use of one or more locking pins. Alternatively,lanyard 109 is used to trigger the extension of the wings and/or tailplanes as well as the engine of the UAV. For example, the wings and/ortail planes could be sprung such that they extend into their flightconfiguration on the lanyard pulling taut and releasing a pin lockingthe wings and/or tail planes in their stowed configuration. The launchcanister could further comprise one or more guide pieces 114, such asrails or a base, expanding or cup type sabot, for guiding the wingsand/or tail planes of the UAV as it passes out of the enclosure andensuring that the UAV enters flight without significant rotation.

The launch canister may further comprise a second lanyard 113 forconnection between the launch canister and the launch platform (e.g. asubmarine launch tube). The second lanyard can be used to activate guideelements of the launch canister. For example, it can be advantageous toequip the launch canister with “steer-away” fins 105 arranged so as to,when deployed, direct the travel of the canister through the water awayfrom the launch platform (e.g. a submarine) and/or ensure that thelaunch canister arrives at the water surface at the optimal angle forlaunch of the UAV. The steer-away fins could be activated on lanyard 113pulling taut when it achieves its maximum extension. For example, thiscould result in one or more shear pins holding the steer-away fins in astowed configuration shearing so as to cause the fins to be deployed(e.g. the fins could be sprung so as to deploy on the shear pins beingremoved).

In order to avoid lanyard 113 being left trailing from the launch tubefrom which the canister is ejected, the lanyard preferably activates theguide elements when it initially pulls taut but then subsequentlydetaches from the launch platform at the launch platform end of thelanyard such that the lanyard escapes the launch platform with thecanister. This can be achieved by having one or more shear pins orswitches at the canister that activate/release at a lower force than therelease means at the launch platform end of the lanyard, with thelanyard remaining connected to the launch canister on the one or moreshear pins or switches being activated/released. The release of thesteer-away fins and the detachment of the lanyard from the launch tubecan be staggered through the use of additional branches of the lanyardpieces at the launch canister, as discussed below in relation to FIG. 2.

Additionally or alternatively, the launch canister could comprise one ormore float devices to aid the launch canister in achieving an optimallaunch angle for the UAV at the water's surface. Inflation of the floatdevices could be triggered by the second lanyard in a similar manner. Incertain embodiments, the second lanyard could also be used to completepower and/or data paths between the launch platform and the UAV.

An exemplary mechanism for launching a canister configured in accordancewith the present invention will now be discussed in relation to FIG. 2A,which shows five phases of a UAV launch. In phase (a), a launch canister200 is ejected in direction 209 by a compressed gas charge from an SSElaunch tube 212 of submarine 201 whilst the submarine is submerged(typically at a depth that allows radio communication between submarineand UAV once the UAV is airborne). A lanyard 204 is connected betweenthe launch canister and launch tube.

At phase (b), the lanyard extends to a predetermined length at whichlanyard branch pieces 206 pull taut and shears pins securing sprungsteer-away fins 205 in a stowed position, allowing the steer-away finsto spring and lock into a deployed position. The remote end 207 oflanyard 204 then detaches from the launch tube 212 at phase (c) inresponse to the main length of lanyard 204 pulling taut at a secondpredetermined length. The steer-away fins act to guide the canister'smotion away from the submarine so as to avoid collision with any partsof the submarine and ensure that the canister maintains a goodorientation for launching its UAV payload.

At phase (d), the launch canister reaches the surface of the water 203and its water surface sensor (not shown in FIG. 2) causes the nose cap208 to be jettisoned and the compressed gas launch mechanism of thecanister to drive the UAV 211 from the canister. As the UAV clears thelaunch canister, its wings and tail planes spring and lock into theirdeployed positions and the engine of the UAV powers up.

It can be seen in phase (e) that the direction 210 in which the UAV islaunched is, in the frame of the canister, substantially in the samedirection as direction 209 in which the canister itself was ejected fromthe launch tube. The canister's momentum from its ejection thereforeaids the launch of the UAV and helps give the UAV sufficient speed(typically at least 12.5 m/s) to achieve flight well above the swell ofthe sea whilst the UAV engine powers up.

FIG. 3 shows a launch canister adapted for launch from an Under CasingLauncher (UCL) of a submarine. UCLs are launch devices provided outsidethe pressure hull of a submarine and configured to eject a payload froma launch tube 301 adapted to withstand the dive pressures experienced bya submarine hull. In FIG. 3, the UCL carries a launch canister 300configured in accordance with the present invention and which in turncarries a UAV 305.

UCL 301 includes a compressed gas charge 302 for ejecting the launchcanister from the tube and an end piece 303 having an electricalconnector for connection to the submarine by means of which power and/ordata can be provided to the UCL. Launch canister 300 comprises anelectrical connector 307 for connection to the UCL and hence to thesubmarine. In this manner the UAV can be charged and/or initialisationand navigation data uploaded to the UAV. The electrical connection tothe launch canister could be provided by a lanyard 113 as discussed inrelation to FIG. 1, but preferably a canister adapted for launch from aUCL does not included a lanyard for tethering to the UCL. This isbecause, due to the location of the UCL tubes on a submarine, steer-awayfins are generally not necessary to steer the launch canister away fromthe submarine. A simple flotation collar 308 can instead be used toguide the motion of the launch canister to the surface and also improveits buoyancy, which allows heavier UAVs to be launched by the mechanismsdescribed herein.

Launch canister 300 operates to launch its UAV in the same manner aslaunch canister 100, with a launch mechanism 306 (e.g. a compressed gascharge) being used to eject the UAV from the launch canister, and nosecap 309 being released to allow the UAV to exit the canister onbroaching the surface of the water. An exemplary launch of a UAV usinglaunch canister 300 will now be described with reference to FIG. 4.

FIG. 4 shows a submarine 401 at periscope depth beneath the watersurface 407 and comprising an Under Casing Launcher 301. Launch canister300 is ejected from the UCL at phase (a) with its subsequent motion inphase (b) through water 402 to the surface being guided by flotationcollar 308 whose inflation could be activated on launch of the canister(e.g. by means of a hydrostatic switch). At phase (c) the launchcanister broaches the surface 407 and in response a surface sensorcauses nose cap 309 to be jettisoned. Further in response to broachingthe surface of water 402, UAV 305 is launched from the canister andhence driven into the air where it enters flight mode and powers away tocomplete its mission.

Whether ejected from an SSE or a UCL, a launch canister according to thepresent invention therefore operates according to the same principles,but it has been found that the preferred guidance mechanisms (e.g. theuse of steer-away fins or flotation devices) employed differ. Moregenerally, however, any of the features of a launch canister describedherein in relation to any of the FIGs. can be used in any combinationwith any other features. The launch canisters and stepwise launchprocedures described herein are merely illustrative and representpreferred embodiments of the present invention. For example, launchcanisters according to the present invention could use both steer-awayfins and floats to guide the passage of the canister through water, orneither such guide elements.

FIG. 5 is a flowchart for ejection of a launch canister from a submergedlaunch platform. The launch canister is ejected at 50 in a directionsubstantially along a first axis of the launch canister. At 52 adetection when a nose cap located in a launch opening of the launchcanister broaches the surface of the water is made.

At 54, in response to the water surface sensor detecting at 52 that thenose cap of the canister has broached the surface of the water, the nosecap is released and a launch mechanism is initiated to drive a unmannedaerial vehicle carried in an enclosure of the launch canister out of thelaunch canister through the launch opening. The unmanned aerial vehicleis then driven out of the launch canister at 56 by the launch mechanismthrough the launch opening in a direction substantially along said firstaxis.

The launch canister and/or the unmanned aerial vehicle (UAV) can beprovided with appropriate control electronics. The control electronicscan comprise apparatus with at least one processor and at least onememory configured to cause performance of the functions of the launchcanister and/or the UAV. A computer program comprising code meansadapted to control, when run on the apparatus can control operations inassociation with launch of the unmanned aerial device from a submergedlaunch platform. More particularly, the apparatus can receive a signalindicating that a nose cap located in a launch opening of a launchcanister carrying the unmanned aerial vehicle and ejected in a directionsubstantially along a first axis of the launch canister has broached thesurface of the water, and in response to the signal, immediately causerelease of the nose cap and initiation of a launch mechanism to drivethe unmanned aerial vehicle out of the launch canister through thelaunch opening. The apparatus can further cause and/or control drivingof the unmanned aerial vehicle out of the launch canister by the launchmechanism through the launch opening in a direction substantially alongsaid first axis.

FIG. 6 shows an example of a control apparatus 70 for a UAV and/or for alaunch canister. The control apparatus can be configured to providecontrol functions in association with the above described launchoperation. For this purpose the control apparatus comprises at least onememory 71, 72, at least one data processing unit 73, 74, and aninput/output interface 75. Via the interface the control apparatus canbe coupled to at least one external sensor and at least one othercontrol apparatus. The control apparatus can be configured to execute anappropriate software code to provide the control functions. The requireddata processing apparatus and functions may be provided by means of oneor more data processors. The data processors may be of any type suitableto the local technical environment, and may include one or more ofgeneral purpose computers, special purpose computers, microprocessors,digital signal processors (DSPs), application specific integratedcircuits (ASIC), gate level circuits and processors based on multi coreprocessor architecture, as non-limiting examples. The data processingmay be distributed across several data processing modules. A dataprocessor may be provided by means of, for example, at least one chip.The memory or memories may be of any type suitable to the localtechnical environment and may be implemented using any suitable datastorage technology, such as semiconductor based memory devices, magneticmemory devices and systems, optical memory devices and systems, fixedmemory and removable memory.

The applicant hereby discloses in isolation each individual featuredescribed herein and any combination of two or more such features, tothe extent that such features or combinations are capable of beingcarried out based on the present specification as a whole in the lightof the common general knowledge of a person skilled in the art,irrespective of whether such features or combinations of features solveany problems disclosed herein, and without limitation to the scope ofthe claims. The applicant indicates that aspects of the presentinvention may consist of any such individual feature or combination offeatures. In view of the foregoing description it will be evident to aperson skilled in the art that various modifications may be made withinthe scope of the invention.

What is claimed is:
 1. A launch canister for ejection from a submerged launch platform, the launch canister being adapted for ejection in a direction substantially along a first axis of the launch canister and for carrying an unmanned aerial vehicle, UAV, the launch canister comprising: a nose cap releasably located in a launch opening at a forward end of the launch canister; a launch mechanism adapted such that when the launch canister carries a UAV and is ejected from the submerged launch platform, the launch mechanism drives, aided by momentum from the ejection of the canister in the direction substantially along the first axis, the UAV out of the launch canister through the launch opening in the direction substantially along the first axis; a water surface sensor for detecting when the nose cap of the launch canister broaches a water surface; a first lanyard attached at one end in the launch canister and having a second end adapted for detachable connection to a UAV, one or more guide elements adapted to direct motion of the launch canister towards the water surface at a preferred launch angle; and a second lanyard fixedly attached at one end to an external part of the launch canister and having a second end adapted for detachable connection to a submerged launch platform; wherein the launch canister is configured to, upon detection that the nose cap of the canister has broached a water surface by the water surface sensor, immediately release the nose cap and initiate the launch mechanism to drive a UAV out of the launch canister through the launch opening in the direction substantially along said first axis, wherein the length of the first lanyard is selected such that, when a UAV is connected to the first lanyard and the UAV is driven from the launch canister, the first lanyard pulls taut and detaches from the UAV as an engine of the UAV passes through the launch opening, wherein said second end of the first lanyard is adapted to cause the engine of the UAV to power up upon pulling taut and detaching from the UAV, and wherein the second lanyard is configured to pull taut at a first extension of the second lanyard when the launch canister is ejected from the submerged launch platform, and the one or more guide elements are configured to move from a stowed to a deployed position upon the second lanyard pulling taut at the first extension of the second lanyard, the first extension of the second lanyard being such that the one or more guide elements are deployed upon the launch canister fully exiting the submerged launch platform.
 2. The launch canister as claimed in claim 1, wherein the launch mechanism is an explosive or high pressure gas charge.
 3. The launch canister as claimed in claim 1, wherein the launch mechanism is initiated in response to the nose cap being released.
 4. The launch canister as claimed in claim 1, wherein the nose cap is connected to the launch canister by means of a sprung hinge, said sprung hinge being biased so as to rotate the nose cap away from the launch opening when the nose cap is released.
 5. The launch canister as claimed in claim 1, wherein the nose cap is connected to the launch canister by means of one or more explosive pins, the nose cap being released from the launch opening by firing the one or more explosive pins so as to drive the nose cap away from the launch opening.
 6. The launch canister as claimed in claim 1, wherein the launch mechanism is an explosive or high pressure gas charge and the nose cap is connected to the launch canister by one or more mechanical locks, the nose cap being released from the launch opening by releasing the one or more mechanical locks and allowing the gas developed by the explosive or high pressure gas charge to drive the nose cap from the launch canister.
 7. The launch canister as claimed in claim 1, wherein the nose cap is configured to make a watertight fit with the launch opening so as to prevent ingress of water into the launch canister during passage of the launch canister through water.
 8. The launch canister as claimed in claim 1, wherein the water surface sensor comprises at least one of a hydrostatic switch, a pressure switch, an electronic switch, and an electro optical switch.
 9. The launch canister as claimed in claim 1, wherein the one or more guide elements include steer-away fins or a flotation device.
 10. The launch canister as claimed in claim 1, wherein the second lanyard is configured to detach from the submerged launch platform upon the second lanyard pulling taut at a second extension of the second lanyard.
 11. The launch canister as claimed in claim 1, wherein the launch canister is adapted for carrying a UAV having stowed wings, the launch canister including one or more guide pieces for guiding passage of stowed wings of the UAV upon such UAV being driven from the launch canister.
 12. The launch canister as claimed in claim 1, wherein the submerged launch platform is a submarine.
 13. The launch canister as claimed in claim 1, wherein the launch canister is adapted for launch from a Submerged Signal Ejector tube or an Under Casing Launcher. 